1. Field of the Invention
The present invention relates to a signal processing device in which an image signal is temporarily stored in a memory and a blanking period is added to the image signal when the image signal is outputted from the memory to allow the image signal to be recorded on or reproduced from a recording medium such as a magnetic disk.
2. Description of the Related Art
In a conventional still video device, when an image signal is recorded on a recording medium such as a magnetic disk, or when an image signal recorded on a recording medium is reproduced, the image signal is converted to a digital signal and temporarily stored in a memory. A horizontal blanking period signal and a vertical blanking period signal are not stored in the memory. Therefore, when the image signal stored in the memory is read from the memory and converted to an analog image signal, a horizontal blanking period signal and a vertical blanking period signal are added to the image signal, and a pedestal level is formed during the blanking periods.
To add the pedestal level to the image signal, an AND circuit is provided between the memory and a D/A converter. Namely, a signal outputted from the memory is prevented from being transmitted to the D/A converter by an operation of the AND circuit, so that a blanking period is formed.
Thus, in the conventional still video device, an AND circuit is provided for forming the blanking period, and therefore, the still video device has a bulky and complex construction.